increment stack all at once; 2% speedup

4 files changed, 48 insertions, 13 deletions

diff --git a/src/analyzer.js b/src/analyzer.js
index ce4a99af..2418170c 100644
--- a/src/analyzer.js
+++ b/src/analyzer.js
@@ -300,7 +300,34 @@ function analyzer(data) {
           });
         });
       });
-      this.forwardItem(item, 'Relooper');
+      this.forwardItem(item, 'StackAnalyzer');
+    },
+  });
+
+  // Stack analyzer - calculate the base stack usage
+  substrate.addZyme('StackAnalyzer', {
+    processItem: function(data) {
+      data.functions.forEach(function(func) {
+        var total = 0;
+        var lines = func.labels[0].lines;
+        for (var i = 0; i < lines.length; i++) {
+          var item = lines[i].value;
+          if (!item || item.intertype != 'alloca') break;
+          // FIXME: This ignores nativized variables, but probably negligible
+          item.allocatedSize = calcAllocatedSize(item.allocatedType, data.types);
+          total += item.allocatedSize;
+        }
+        func.initialStack = total;
+        var index = 0;
+        for (var i = 0; i < lines.length; i++) {
+          var item = lines[i].value;
+          if (!item || item.intertype != 'alloca') break;
+          index += item.allocatedSize;
+          item.allocatedIndex = index;
+          delete item.allocatedSize;
+        }
+      });
+      this.forwardItem(data, 'Relooper');
     },
   });
 
diff --git a/src/jsifier.js b/src/jsifier.js
index 547bde72..955fa900 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -276,7 +276,9 @@ function JSify(data) {
       }).filter(function(param) { return param != null });;
 
       func.JS = '\nfunction ' + func.ident + '(' + params.join(', ') + ') {\n';
-      func.JS += '  ' + RuntimeGenerator.stackEnter() + '\n';
+
+      func.JS += '  ' + RuntimeGenerator.stackEnter(func.initialStack) + ';\n';
+
       if (LABEL_DEBUG) func.JS += "  print(INDENT + ' Entering: " + func.ident + "'); INDENT += '  ';\n";
 
       if (true) { // TODO: optimize away when not needed
@@ -591,15 +593,10 @@ function JSify(data) {
     return item.ident + '.f' + item.indexes[0][0].text;
   });
   makeFuncLineZyme('alloca', function(item) {
-    dprint('alloca', dump(item));
-    if (pointingLevels(item.allocatedType) == 0 && isStructType(item.allocatedType)) {
-      return RuntimeGenerator.stackAlloc(makeEmptyStruct(item.allocatedType).length);
-    } else {
-      return RuntimeGenerator.stackAlloc(1);
-    }
+    assert(typeof item.allocatedIndex === 'number'); // or, return RuntimeGenerator.stackAlloc(calcAllocatedSize(item.allocatedType, TYPES));
+    return getFastValue('STACKTOP', '-', item.allocatedIndex.toString());
   });
   makeFuncLineZyme('phi', function(item) {
-    dprint('phi', dump(item));
     return '__lastLabel__ == ' + getLabelId(item.label1) + ' ? ' + toNiceIdent(item.value1) + ' : ' + toNiceIdent(item.value2);
   });
 
@@ -612,7 +609,6 @@ function JSify(data) {
   }
 
   makeFuncLineZyme('mathop', function(item) { with(item) {
-    dprint('mathop', 'mathop: ' + dump(item));
     for (var i = 1; i <= 4; i++) {
       if (item['param'+i]) {
         item['ident'+i] = finalizeLLVMParameter(item['param'+i]);
@@ -705,7 +701,7 @@ function JSify(data) {
       } else if (b == 1) {
         return a;
       }
-    } else if (op == '+') {
+    } else if (op in set('+', '-')) {
       if (!a) a = 0;
       if (!b) b = 0;
       if (a == 0) {
diff --git a/src/parseTools.js b/src/parseTools.js
index 4d1ed438..ca96ba65 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -446,3 +446,11 @@ function cleanLabel(label) {
   }
 }
 
+function calcAllocatedSize(type, TYPES) {
+  if (pointingLevels(type) == 0 && isStructType(type)) {
+    return TYPES[type].flatSize; // makeEmptyStruct(item.allocatedType).length;
+  } else {
+    return 1;
+  }
+}
+
diff --git a/src/runtime.js b/src/runtime.js
index 346020b0..0ae70fa3 100644
--- a/src/runtime.js
+++ b/src/runtime.js
@@ -25,8 +25,12 @@ RuntimeGenerator = {
     return ret;
   },
 
-  stackEnter: function() {
-    return 'STACK_STACK.push(STACKTOP);';
+  stackEnter: function(initial) {
+    var ret = 'STACK_STACK.push(STACKTOP); STACKTOP += ' + initial;
+    if (GUARD_MEMORY) {
+      ret += '; assert(STACKTOP < STACK_MAX)';
+    }
+    return ret;
   },
 
   stackExit: function() {